Sedentary Behavior

Exercise psychology has evolved from sport and health psychologies and has involved the study of psychological antecedents (e.g., motivational and other influences) and consequences (e.g., mental health effects) of participation or nonparticipation in moderate-to-vigorous physical activity (MVPA). It is now widely recognized that a lack of MVPA (inactivity) is a major public health issue. It is also believed that similar health problems can arise from too much sitting (sedentary behavior).

Sedentary is a term often used to describe individuals with low PA or not meeting a criterion level of PA. However, it is recommended not to define sedentary behavior in this way but instead to define it as sitting or lying behaviors undertaken in waking time. This encompasses behaviors associated with the use of technology (e.g., TV, computer), socializing (e.g., sitting and talking), travel (e.g., motorized transportation, especially car use), and other common sitting behaviors (e.g., reading). Some of these are changing rapidly, such as computer gaming, and may pose significant health risks if sedentary time is excessive. Such risks can occur even when PA levels meet guidelines. One important issue for psychologists is how to effect behavior change—that is, to help people sit less. This is different from “moving more” at the level of MVPA.

Little research has taken place on the psychology of sedentary behavior. It has been found that sociodemographic (e.g., social class), behavioral (e.g., smoking) and environmental (e.g., having TV in bedroom) variables are all associated with screen time (TV and computer use), but no consistent psychological correlates consistently emerge from such analyses. Psychology may operate indirectly, such as through the negotiation of use of electronic equipment in the home or parents discussing rules about screen use for their children, but few data exist showing consistent psychological correlates of sedentary behavior in young people or adults.

Typical theories used in exercise psychology to help explain participation in PA are social cognitive theory (SCT), theory of planned behavior (TPB), and the transtheoretical model (TTM). These may not necessarily be appropriate for the study of sedentary behavior. Behavioral choice theory has been used in sedentary behavior research and suggests that behavior is a function of the ease or difficulty of access and availability of sedentary pursuits and the reinforcement value (e.g., enjoyment) of such behaviors. Access and availability are likely to be high for many sedentary behaviors. The enjoyment of some sedentary behaviors, such as computer games, could also be high. This might make sedentary behavior reduction a significant challenge.

Anecdotally, sedentary behaviors seem to be as much about “habit” than conscious or deliberate decisions. Health behavior change can be achieved in one of two ways. There is the “deliberative route,” where people use thoughts and conscious processing to arrive at decisions and behaviors. However, there is also the “automatic route,” whereby people are influenced in their behavior by environmentally cued responses, habit, and little or no conscious processing. For example, when entering a room with chairs, little or no conscious processing is involved in sitting. No “decisions” are made; most people just sit. Habit will be clearly associated with a behavior if everyday contexts remain stable and are regularly encountered. Clearly, this is the case for sitting. On the other hand, there may be contexts, particularly if people become more aware of the health consequences of prolonged sitting, where more conscious thoughts are used to stand and move. Promoting such behaviors may be beneficial. In short, psychologists may wish to account for more habitual processes in sedentary behavior than has typically been the case for PA. This might involve promoting less sitting with signs and reminders.

Interventions to reduce sedentary behavior have been reported almost exclusively on young people. The overall effect is small but meaningful. The small effect may reflect sedentary behavior being a challenging behavior to change, driven by strong habitual tendencies and social norms.

Approaches to change sedentary behaviors in young people have generally included educational and family interventions, with the former aiming to teach children about sedentary behaviors (e.g., TV viewing) and how to seek alternatives. This is best illustrated by the Planet Health program in the United States, where children study a “power down” TV reduction element alongside other aspects of health. Other intervention approaches have included the use of TV and computer time budget monitors. With adults, studies are emerging that tackle sitting in the workplace, such as through the introduction of standing desks or goal setting.

Sedentary behavior has become a popular area of research although the number of psychological studies is currently small. However, as we move to greater use of interventions, the role of psychology should develop. But much more needs to be known about how we might change such behaviors. This is at a time of an environmental onslaught that encourages and reinforces such behaviors. Psychologists will need to explore what is realistic for sedentary behavior change, how best to prompt and reinforce sedentary behavior change, and to consider what theories or perspectives work best. Moreover, more knowledge on how to communicate this “new” health message is also needed.